年号是封建帝王为纪念在位之年而特立的名号，也是史家用以纪年的方法。这种年号纪年法创始于西汉的汉武帝刘彻，但不是他即位之初就有的。汉武帝即位２６年有司上奏：“元宜以天瑞命，不宜以一二数。”恰好第二年就发现宝鼎，这才有了“元鼎”这个年号。又将此以前的年号... The year is a feudal emperors in order to commemorate the year and the special legislation of the name, but also the method used by historians to the year. This chronology was founded in the Han Wudi Liu Che of the Western Han Dynasty, but not as early as he ascended the throne. Ascended the throne of Emperor Wu of the Han ascended the throne: “Yuan Yi Tian Rui life, should not be one or two.” Just the second year found Baoding, this has “Yuan Ding” this year. Again before this year's number ...